Scientists develop technique to reduce cost, environmental impact of mining precious metal

Researchers at the University of Notre Dame invented a new class of molecules whose shape and size enable them to capture and contain precious metal ions.

In a study published in the Journal of the American Chemical Society, the scientists explain that the method they have developed converts gold-containing ore into chloroauric acid and extracts it using an industrial solvent. The container molecules are able to selectively separate the gold from the solvent without the use of water stripping.

“Our newly developed molecules have the ability to eliminate this need for water stripping and facilitates solvent recycling in this alternative mining process,” said the paper’s senior author and Professor of Chemistry and Biochemistry at Notre Dame, Bradley D. Smith in a media brief. “Currently, most of the world’s gold mining relies on a 125-year-old method that treats gold-containing ore with large quantities of poisonous sodium cyanide, which is extremely dangerous for mine workers and can cause environmental issues.”

Smith also said this new process has a milder environmental impact and that, besides gold, it can be used for capturing other metals such as platinum and palladium.

The researcher added that the technique could be implemented in ‘urban mining’ processes, such as those that imply removing precious metals from wastewater streams.